Tim Wusz of Rockett made a...
Tim Wusz of Rockett made a career out of supplying racing fuels and understands the needs of different engines.
As Pontiac hobbyists we often state that, “We have gasoline running through our veins.” To many of us, life without the chemical-to-mechanical energy conversion that occurs inside the combustion chamber would seem almost unbearable. Even those passionate about the subject still know very little about the fuel that is a major focus of our interest. We know there are varied grades of gasoline, the stuff sold today is different from back in the glory days, and at the track you use race gas—and that’s about it. If that is the case with you, then this story will be an eye-opener.
It is important to state early on in this primer that as the author, I, too was in the same situation as you when it came to a knowledge of gasoline. A few years back, I had the wonderful opportunity to spend an entire day at the research laboratory of a major oil company with the head engineer and chemist to entertain my questions. I learned more about fuel in that day than I had collectively over the course of my lifetime. Even after that experience I am still no expert, especially when it comes to the interaction of today’s fuel in a traditional Pontiac engine. It seems that modern gasoline has become the whipping boy for many things wrong under the hood of an older Pontiac. Is this fact or fiction? We need to find out.
This article is the result of another primer in this issue of HPP, where we take a ’73 SD-455 and run it on a dyno with four different fuels—some that are not even available to the public yet. At HPP, we know that if we have questions about how a Pontiac engine performs on modern fuel, you, as readers, have the same queries.
A true race gasoline is modified...
A true race gasoline is modified for best performance, but usually sacrifices other factors, such as cold weather starting and warm up. For almost any street/strip Pontiac, the 100 octane unleaded is an excellent choice that retains street-gas startability. It’s offered in metal five-gallon cans that can be shipped to your home. Shown also is the 118-octane product.
As we moved forward collecting the empirical data on the Pontiac engine with the varied fuel compositions, it quickly became apparent that this experiment was so cutting edge, it would leave many questions unanswered if we did not back it up with a proper explanation. Wanting to provide our readers with a comprehensive analysis of fuel led us to include this overview of gasoline, a one-two punch of the theoretical and empirical that is required to be successful in extracting the most horsepower from a Pontiac engine.
Rockett Brand Racing Fuel stepped up, provided the necessary fuel for the dyno test, and allowed us to pick the brain of one of the most respected names in the industry, Tim Wusz. He has made a career out of blending and testing all types of fuel with his initial position at the Union 76 oil company. He is now a key technical component behind the formulation and success of the Rockett Brand racing gasoline. In addition, he is a “grease under the fingernails” engineer that has a collection of musclecars and drives a modern Pontiac GTO.
Gasoline, like many energy products, is paid for and the work it produces is realized but rarely ever seen. This is especially true with a newer engine equipped with an EFI system—at least with a carburetor you can move the throttle and see the accelerator pump stroke discharge fuel into the booster. In contrast to most things in a Pontiac that are mechanical, becoming familiar with gasoline requires us to think in the abstract, since it has more to do with chemistry than anything else.